The conservative Republican from Utah suppressed a mischievous grin and leaned toward the liberal Democrat from Massachusetts.

"Ted, if you keep getting into trouble, I'm going to lose my temper and I'm going to send the Mormon missionaries after you," Sen. Orrin Hatch told Sen. Edward Kennedy."He got kind of a wistful, almost tearful look in his eye," Hatch said later, describing the scene, "and said, `Orrin, I'm just about ready for them.' '

Once again, 22 years after Chappaquiddick, the glare of public scrutiny and the noise of a media circus surround Kennedy's private life. This time, police are investigating an allegation that Kennedy's nephew, William Kennedy Smith, raped a woman in the early morning hours of March 30 at the family compound in Palm Beach, Fla.

Kennedy's own conduct that Easter weekend also has been criticized.

Now back in the Senate, where he has served nearly three decades, Kennedy could not hide his exposed public side.

"He's gone through hell. I know that personally," said Hatch. "He's very hurt by this. You won't see that."

Kennedy, while insisting that the allegation of rape leveled against his nephew has had no effect on his own work, acknowledges he is not above criticism for his behavior in Florida.

"All of us have always understood that there are things that you can and should do differently and I've certainly recognized that fact and we just have to go on from there," Kennedy said.

In this case, those "things" include drinking at the Au Bar club in Palm Beach into the early morning hours with his son Patrick and Smith and returning to the compound with 27-year-old Michelle Cassone. Kennedy denied Cassone's contention that he appeared before her wearing an Oxford-cloth shirt and no slacks.

Arguably the most famous politician in America outside the president, Kennedy, 59, at times does a better job staying out of the spotlight in Washington than in social settings. Kennedy has done some of his best work in the Senate behind closed doors, in bare-knuckle negotiating sessions with his conservative friend, Hatch, or with White House chief of staff John Sununu.

His power on Capitol Hill is illustrated by the reaction - or non-reaction - of colleagues and lobbyists to what former President Nixon called "some sort of sexcapade" in Florida.

While constituents, columnists and "Saturday Night Live" comedians lampoon Kennedy, those who work with and watch him steadfastly refuse to criticize him.

Instead they talk about one of his lesser-known attributes: the ability to get liberal legislation passed into law during a conservative ascendancy.

In the 101st Congress alone, Kennedy helped push into law the first comprehensive child care legislation, an increase in the minimum wage, expansion of the Head Start program, the landmark Americans with Disabilities Act and a comprehensive AIDS funding bill.

This year, he's at the center of legislative maneuvering over a civil rights bill. And as chairman of the Senate Labor and Human Resources Committee, he's pushing for a new mandatory spending program for children and increased aid to higher education.

Leaders of women's rights groups stand by Kennedy.

"Sometimes the famous family facade diverts attention from the real, substantive issues," said Patricia Ireland, executive vice president of the National Organization for Women. "On the substantive issues, Ted Kennedy has always been on the right side."

Hatch, as ranking Republican on the Senate labor panel, knows the power of Kennedy and of the liberal groups that form his support.

"When you go up against Kennedy, it's like going up against a freight train," Hatch said. "I think I'm an authority on this."

In the money-driven world of Washington politics, the American Conservative Union renders the highest possible compliment: It prints Kennedy's name on virtually every fund-raising letter it mails out. The message is simple: If you want to stop Ted Kennedy, give us money.

"We wouldn't be where we are today without Ted Kennedy," said ACU legislative director Bob Billings.

Senate Majority Leader George Mitchell, D-Maine, said Kennedy is "one of the most effective members of the Senate," not because of his strident liberalism but because of his willingness to negotiate.

It also helps that he's no longer an evergreen on the list of possible presidential candidates.

"Being a candidate for president, you're able to get more focus and attention on the issues," Kennedy said. "Not being one, you increase your credibility on the issues."